Cardiovascular diseases among Greenland Eskimos are rare because their diet is rich in fatty fish and marine mammals. The beneficial effect of the fish diet appears to be mediated, at least in part, by the high amount of eicosapentaenoic acid in fish. We investigated the total lipid amount and fatty acid composition of 12 commonly eaten North-European fish species. Most of the detected fatty acids were unsaturated, and the content of eicosapentaenoic acid varied usually between 6 and 16%. The amount of total lipid varied between 3.5 and 216 mg/g wet tissue. The total amount of lipid in different fish species seems to be more important than the respective fatty acid composition when considering which fish should be especially beneficial in the diet. Herring, salmon, Baltic herring, turbot and trout seem to contain most abundantly eicosapentaenoic acid.